John Paul M. Joaquin Science 03.28.2022 05:Mar AM EDT

NASA Reschedules Mars Sample Return Campaign — Why the Delay?

Perseverance's Martian rock samples will have to wait a bit longer to see Earth.

The National Aeronautics and Space Administration (NASA) recently announced it has plans to delay the Mars Sample return campaign to reduce the overall risk of the program, per Space News.

NASA's Mars Sample Return Delay Details

NASA Associate Administrator for Science Thomas Zurcuchen revealed at the latest National Academies' Space Studies Board that NASA and the European Space Agency (ESA) have agreed to make revisions on the schedule and design for upcoming missions that will return the Martian rock samples gathered by NASA's Perseverance rover back to Earth.

According to the ESA's return mission concept, the original mission involves sending a Sample Lander to land near Perseverance's land site and deploying a Sample Fetch Rover to find NASA's Mars rover and collect the gathered samples once it does. After which, the rover will return to its lander, load them into a single large canister on the Mars Ascent Vehicle, which will liftoff from Mars and carry the container into the planet's orbit.

The Mars Ascent Vehicle will then wait for an Earth Return Orbiter that will capture the canister containing the samples and then seal it in a biocontainment system. The orbiter will then return to Earth and release the entry capsule for the samples to end up in a specialized handling facility.

This mission would have returned the samples to Earth in 2031.

The revised version of the mission called for a split on the lander missions into two separate spacecraft to reduce the overall risk of the program: one to carry the Sample Fetch Rover to Mars, while the other contains the Mars Ascent Vehicle.

An Independent Review Board report also recommended delaying the mission's launch to 2027 or 2028 to provide a more reasonable development schedule.

Zurbuchen mentioned that NASA and the ESA agreed to the recommendations and revised their plans for the return mission, thereby splitting the Sample Retrieval Lander into two landers and launching the mission in 2028.

With this revised plan, the Martian rock samples are expected to be on Earth by 2033, two years later than the original plan.

"The Phase A analysis demonstrated that, frankly, the single lander breaks entry, descent, and landing heritage," Zurbuchen said. "It is actually high risk."

Differences Between Single-Lander and Dual-Lander Approaches

An American Institute of Physics report about the delay mentioned that Zurbuchen said that using a single lander to carry both vehicles would have departed too far from established technologies, which introduces an unacceptable risk. Doing so would require a larger heart shield, which would require a larger payload fairing for the rocket launching it.

The lander's design also had "unproven" entry, descent, and landing capabilities which requires electric propulsion and the lander's cruise stage to increase its payload performance.

A dual-lander, meanwhile, would allow NASA and the ESA to use the same landing system Perseverance and Curiosity previously used as well as the chance to avoid the complexity of the single-lander design.